1. Field of the Invention
This invention relates to an electrical connector for connection to a flat cable formed by film-coating conductive lines in the form of plate-like conductors, such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable), and in particular relates to an electrical connector, particularly a so-called back-flip electrical connector, adapted to be surface-mounted on a printed board.
2. Description of Related Art
A mobile electronic device such as a mobile telephone, a smartphone, or a tablet is always required to be reduced in size and thickness for reasons such as improving the operatability thereof and, therefore, an electrical connector (hereinafter may also be referred to simply as a “connector”) to be incorporated in such a device is also inevitably required to be reduced in size and thickness.
As a connector of the type that is advantageous in reducing the thickness of a device, there is a so-called back-flip connector. This type of connector has a lever called an actuator at a position behind an opening which is provided for insertion of a cable therethrough. Hereinafter, in this specification, the side where the opening for insertion of the cable is provided will be referred to as the front of the electrical connector while its opposite side will be referred to as the rear of the electrical connector.
Usually, in the back-flip connector, when establishing electrical connection to the cable inserted through the opening, the actuator is tilted to the rear to press contacts in the connector against conductors of the cable, while, when detaching the attached cable, the actuator is raised to separate the contacts from the conductors. Since the actuator is in the tilted state while the cable is attached, it is possible to reduce the height of the connector attached with the cable.
On the other hand, a processor installed in an electronic device such as a smartphone has been increasing in speed year by year. Consequently, higher-speed signal transmission is carried out in wiring and an electrical connector in the electronic device. With the increase in transmission speed, a measure is required for a noise electromagnetic wave at a relatively low level which has not been a problem in the past.
For example, when a connector is surface-mounted on a printed board, terminals of the connector and signal wiring patterns on the printed board should be brought into contact with each other and electromagnetic waves may be generated at these contact portions. In order to prevent these electromagnetic waves from leaking to the outside of the connector, it may be considered to cover the entire connector with a conductor layer connected to ground, i.e. a shield.
Herein, if an attempt is made to cover the entire back-flip connector with a shield, the connector can be relatively easily covered with the shield on its front and lateral sides. However, the shield cannot be easily provided on the rear side of the connector due to various problems.
It may be considered to dispose a shield shell that covers the rear side of an actuator tilted to the rear. If such a shield shell is provided, it is possible to shield electromagnetic waves directed to the rear of the connector from contact points between the connector and the printed board. However, there is a possibility that providing such a shield shell may cause an increase in the size of the connector.
If the contact points as noise sources are present right under the actuator, it is necessary to consider to shield electromagnetic waves that advance directly upward from the contact points. In this event, it may be considered to provide a high shield that covers even the actuator in an upright state. However, in this case, an increase in the height of the entire connector is induced.
Alternatively, it may be considered not to provide, before a cable is attached, a shield for electromagnetic waves that advance directly upward from the contact points, and to carry out an operation of disposing a shield to cover the upper side of the actuator after the actuator is tilted to the rear to cause the cable to be attached. In this case, while it is possible to avoid an increase in the height of the connector, the connector mounting operation may become difficult.
Japanese Patent (JP-B) No. 4837711 (hereinafter referred to as “Patent Document 1”) describes a surface-mount connector which relates to this invention. The connector described in Patent Document 1 is basically a so-called front-flip connector. Patent Document 1 describes an electrical connector that forms a shielding path through a path including a shield layer of a flat cable, thereby allowing a shield plate, provided to an actuator, to exhibit a shielding effect. As shown in FIG. 32, in Patent Document 1, electromagnetic waves that advance toward the rear of the electrical connector are dealt with by providing a shield shell 102 “which is formed by punching a plate made of a conductive material and partially covers an upper surface, both side surfaces, and a rear surface on the rear end side of a housing 11 (housing 101 in FIG. 32)” (paragraph [0021]).
This invention has been made under these circumstances and it is an object of this invention to provide a back-flip electrical connector which is small and thin while having a shield for shielding an electromagnetic wave at a rear portion of the electrical connector and which does not require adding a separate shield shell for covering the rear side of the electrical connector after the electrical connector is mounted on a board.